1. FIELD OF THE INVENTION
The present invention relates to apparatus for heating the operator's compartment of a motor vehicle of the heavy, earth moving type with air heated by the vehicle radiator.
2. DESCRIPTION OF THE PRIOR ART
The problem of heating an open operator's compartment in heavy equipment vehicles has existed for some time, and numerous attempts to solve this problem have been proposed. One advantageous method exploits rejected heat from the radiator, and to conduct air heated thereby to the operator's compartment. The following patents illustrate this approach.
U.S. Pat. No. 1,446,725, issued to Herbert D. Shamberg on Feb. 27, 1923, discloses a heating system conducting heated air from the radiator at the front of the vehicle to the operator's compartment through a duct located within and against the hood of the vehicle. A second wall substantially parallel to the hood is provided just inside the hood. Heated air flows through the space therebetween. The air is forced by the engine fan.
U.S. Pat. Nos. 2,920,829 issued to Charles W. Shane on Jan. 12, 1960, and 3,155,318, issued to Arthur J. Kirkham on Nov. 3, 1964, disclose arrangements wherein a shroud is placed over the front of the radiator of an agricultural tractor. In each case, the shroud is for temporary use, made from fabric or flexible material. A conduit draws air from inside the shroud, and conducts this air to the operator's area of the tractor. The vehicle fan is arranged to discharge air to the front of the radiator, where it is collected by the shroud and conducted to the operator.
Permanent shrouds made from metal or other stout material are seen in U.S. Pat. Nos. 4,093,119, issued to Edmund Swisher on Jun. 6, 1978, and 4,252,271, issued to William R. Green on Feb. 24, 1981. The shroud of Swisher incorporates a filter for removing dust from the air, and has louvers selectively movable to adjust the amount of air directed back to the operator. A flexible conduit conducts heated air to a diffuser mounted in the operator's compartment.
U.S. Pat. No. 4,612,975, issued to Masanori Ikari on Sept. 23, 1986, discusses heating and cooling of an operator's compartment. Ikari provides an air duct located beneath the floor of the compartment for conducting air from a mixing chamber to individual blow ports, or air diffusers.
U.S. Pat. Nos. 2,584,329, issued to Clyde E. Clapper on Feb. 5, 1952, and U.S. Pat. No. 4,616,483, issued to Kerney T. Sheets on Oct. 7, 1986, disclose heating arrangements wherein air deflector panels are disposed about the engine compartment, for guiding warmed air towards the operator.
It should be noted that in all of the above references, an air flow path is disposed at the sides of or above the engine compartment and main bodywork of the respective vehicle. This flow path is defined by conduits provided for the purpose, or by auxiliary bodywork. Both types of structure are external to the vehicle, and subject to damage should the vehicle contact solid environmental objects, or tip over. These conduits and deflector plates may also obscure the operator's vision.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.